Answer:
9 hours
Step-by-step explanation:
"At the same rate" means time and wages are proportional.
time/wages = t/$108 = (13 h)/$156
t = 108(13 h)/156 . . . . . . . . . . . . . . . units of dollars cancel
t = 9 h
Chang would have to work 9 hours to make $108.
